1. Field of the Invention
The present invention relates to an arc resistant terminal and an arc resistant terminal pair used for electrical connection in the application of a high voltage in an automotive vehicle or the like and an automotive connector (e.g. a connector, a joint box) provided with such a terminal.
2. Description of the Related Art
Connectors used in an automotive vehicle or the like may be detached with a frequency of about once every several months or once every several years for the maintenance and inspection of the automotive vehicle or the like. However, there is a danger of creating an arc discharge between the terminals of the connector the moment they are separated. Particularly, in recent years, a progress has been made to further increase a battery voltage to about DC36V instead of confining it to about DC12V of conventional use. Thus, there is a danger of creating a fairly large arc. The terminals are thought to be damaged due to such an arc. For example, a male terminal is normally bar-shaped or plate-shap d, and has its leading end portion slightly pointed in order to facilitate the insertion into a female terminal. The pointed leading end portion is fused by the repeated connection and separation of the male terminal with and from the female terminal and the accompanying repeated occurrence of the arc discharge, and a fused part is cooled and solidified after slightly moving toward a base end of the male terminal. Thus, the leading end portion becomes round and bulges out. In other words, there is a possibility that the terminal is considerably deformed, which may result in a contact failure and may, in a worst case, make the male terminal fitting unable to be inserted into the female terminal.
As a measure to avoid such an inconvenience caused by the arc discharge. Japanese Unexamined Patent Publication No. 2001-266985 (pages 2 to 4) discloses a male terminal in which a resistance element unlikely to create an arc discharge is attached to the outer surface of a leading end portion of a conductive plate forming the male terminal, and the conductor plate is in contact with a female terminal when the male terminal is completely connected with the female terminal, whereas the resistance element is separated last from the female terminal when the two terminals are separated, thereby suppressing an occurrence of an arc discharg in the moment of separating the male and female terminals.
The above publication discloses the use of carbon and tungsten as the resistance element. However, for example, tungsten creates an arc discharge with a power supply voltage DC of a circuit=36V and a current between terminals=30A. Thus, tungsten cannot be used for terminals used in an environment whose voltage and current are to be further increased in the future. In the case of using carbon as the resistance element, adherence to the conductive plate is low and such a resistance element may come off the conductive plate to expose the conductive plate. Therefore, there has been a demand for a measure to more securely suppress an occurrence of an arc discharge.